The present invention relates to a control method for displaying an image of a virtual reality space on a head tracking-type head mounted display (HMD) worn by a user and outputting sound of the virtual reality space to a headphone worn by the user.
There are publicly known virtual reality (VR) techniques for providing three-dimensional images and stereophonic sounds to the user such that the user can feel as if he/she is in a virtual reality space.
In addition, as a technique for audio expression of virtual reality, Japanese Patent Application Publication No. 2002-51399 discloses a technique for reducing a process load in the presence of a large number of mobile sound sources. Japanese Patent Application Publication No. 2007-50267 discloses a technique for detecting the position relative to a mobile sound source, and changing sequentially parameters for sound image localization to implement accurate sound image localization in synchronization with the motion of the mobile sound source.
In the consumer VR environment providable at relatively low prices at the current technical level, the player merely has a VR-type HMD with a head-tracking function on his/her head and a game controller by hand, and no reproduction of tactile sense and force sense has been yet achieved.
On the other hand, to provide virtual reality experience during gameplay, it is necessary to prepare some story for entertainment. In addition, the presence of props is meaningful to move the story smoothly. It is an important technical issue to reproduce realistic sounds of the props used by the player in a virtual reality space for improvement of a sense of immersion.
For example, imagine a scene in which the player holds and uses a virtual cell phone in a virtual reality space. The virtual cell phone is off course not existent in actuality, and thus the player acts as if he/she picks up the non-existent cell phone, puts it close to his/her ear, and starts communications virtually. Since it is not possible to reproduce a force sense of holding the virtual cell phone or a detailed tactile sense of pressing a call button or the like, the reality of VR experience greatly depends on how to reproduce real sounds related to the virtual cell phone.
The same thing can be said to other examples such as a scene in which the player holds and uses a virtual radar sensor like a metal detector and a scene in which the player holds and uses a virtual directive microphone.